Field of the Invention
The present invention relates to a water-based ink for ink-jet recording, an ink cartridge, and an ink-jet recording method.
Description of the Related Art
Ink-jet recording is conventionally performed by using water-based pigment inks for ink-jet recording in which pigments are used as colorant. The typical water-based pigment inks suffer from the problem of rubbing resistance in which a part of the pigment jetted on a recording medium remains on a surface of the recording medium and the remaining pigment peels off from the recording medium when being rubbed by a finger or the like. In order to solve the problem, Japanese Patent Application laid-open No. 2006-273892 corresponding to United States Patent Application Publication Nos. 2009/0220748 and 2013/0235117 discloses an approach in which a polymer is added to the water-based pigment ink to improve the rubbing resistance on the recording medium.
However, adding the polymer to the water-based pigment ink in an excessive amount for the purpose of improving the rubbing resistance may cause the following problem. Namely, when moisture or water in the water-based pigment ink evaporates, the polymer increases the viscosity of the water-based pigment ink to affect maintenance performance. Further, recent ink-jet recording using the water-based ink for ink-jet recording needs higher quality images and higher speed operation. Thus, a water-based pigment ink for ink-jet recording which has a better rubbing resistance in recording on glossy paper is required.
In view of the above, an object of the present teaching is to provide a water-based pigment ink for ink-jet recording which has a good rubbing resistance in recording on glossy paper and is less likely to increase the viscosity after evaporation.